Temperature is an environmental condition that is often measured to obtain temperature measurements that can be important to the operation of many systems. Most physical, electronic, chemical, mechanical and biological systems and their associated processes are affected by temperature. Some processes only operate adequately within a particular range of temperatures. When these processes need to be optimized, control systems that keep temperature within specified limits can be used to manage temperature. Temperature sensors are devices that provide input measures of the temperature to those control systems.
Many electronic components can be damaged by exposure to excessively high or low temperatures. Semiconductor devices and LCDs are examples of commonly used components that can be damaged by temperature extremes. When temperature limits are exceeded, action must be taken to protect the exposed system. Temperature sensing is an important component of any reliable measure to protect devices from exposure to excessive temperatures.
An example of a system that uses temperature sensors to manage the temperature of its components is a personal computer. It should be appreciated that a personal computer's motherboard and hard disk drive generate a significant amount of heat. An internal fan can be used to help manage the heat that is generated. However, if the internal fan fails, or the flow of air is blocked, permanent damage can result. By sensing the temperature inside the case of the personal computer, high temperature conditions can be detected and actions can be taken to reduce system temperature, or even to shut down the system to avert catastrophe.
Other applications simply require temperature data that can be provided by a sensor so that the effect of temperature on a process can be accounted for. Such applications can include processes where optimum temperatures must be identified, processes where temperature variation needs to be tracked, and processes where knowing a temperature level enables compensation.
Settling time is the time required for nodes of a temperature sensor to settle. The settling time of a temperature sensor is a crucial factor in the measurement of temperatures. For an accurate measurement, the node from which a measurement is taken must settle. If settling time is too long then a measurement of temperature provided by a temperature sensor can take too long to effectively respond to the measured temperature condition (e.g., to prevent damage). Moreover, the faster a measurement can be provided the faster the response to a temperature condition can be made. Many of the conventional temperature sensors that are currently in use include inadequate systems for reducing settling time.